(19)
(11) EP 0 657 839 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.06.1997 Bulletin 1997/23

(43) Date of publication A2:
14.06.1995 Bulletin 1995/24

(21) Application number: 94119409.4

(22) Date of filing: 08.12.1994
(51) International Patent Classification (IPC)6: G06K 9/48
(84) Designated Contracting States:
DE ES FR GB IT

(30) Priority: 10.12.1993 JP 310694/93
10.12.1993 JP 310696/93
15.02.1994 JP 18591/94
23.03.1994 JP 52286/94

(71) Applicant: Ricoh Company, Ltd
Ohta-ku Tokyo 143 (JP)

(72) Inventors:
  • Tachikawa, Michiyoshi
    Yokohama-Shi, Kanagawa-Ken (JP)
  • Miyazawa, Toshio
    Kawasaki-Shi, Kanagawa-Ken (JP)
  • Hirano, Akihiko
    Nerima-Ku, Tokyo (JP)

(74) Representative: Schwabe - Sandmair - Marx 
Stuntzstrasse 16
81677 München
81677 München (DE)

   


(54) Method and apparatus for extracting and recognizing a specific image from an imput image signal


(57) A circumscribing rectangle is obtained for a black continuous image part using a two-tone image signal. If it is determined (in S105) that the image part is possibly one which is obtained as a result of rotating the object, lengths of sides of the image part are compared with threshold values (in S106 and S108). If it is determined (in S105) that the image part is not one which is obtained as a result of rotating the object, the height and horizontal length of the circumscribing rectangle are compared with the threshold values (in S107 and S108). Thus, it is determined (in S115 and S116) whether or not the image part is identical to the object. An RGB chromaticity histogram is produced for each of small regions of an input color image (in S202A). Each of the chromaticity histograms of the small regions is compared with reference ones (in S202A). As a result of the comparison, an identification number of the reference histogram having the highest similarity to that of the small region among those constituting the input image is given to the small region (in S204). A histogram of the identification numbers thus is produced for the input color image (in S204). The thus-produced histogram is used to determine (in S205) which one of a plurality of objects is identical to the input color image.






Search report